It has long been accepted that in humans, blinking of the eyes serves to cleanse and lubricate the corneal surface, and that the rate of blinking and other measures of blinking could be attributed to environmental conditions (such as humidity and particulates in the air). It has also been postulated by investigators that blinking is strongly influenced by other factors such as fatigue and drowsiness, and may be monitored to provide some indication of alertness, which is used herein to mean the absence of fatigue and drowsiness.
The ability to measure alertness, or to detect the absence of alertness or presence of fatigue or drowsiness is desired. Many work assignments require a high level of alertness, often in environments not conducive to maintaining alertness. Examples of these are: nuclear reactor operators, aircraft pilots and other operators of complex equipment, air traffic controllers and others whose work environments provide little visual stimulus of a non-monotonous nature. Often consequences of lapses in alertness in these conditions can be grave, involving a high degree of hazard to life and property. It is this connection that has led the inventors to develop this method and apparatus for detection of alertness.